Frequently, accessory elements such as kickstands, luggage carriers, baskets, and the like, are attached to cycles. To attach the accessory, it is customary to clamp a counterelement on the accessory, or secured thereto against a clamping plate, with parallel or essentially parallel struts of the cycle frame interposed. The counterelement and the clamping plate are then clamped together by a screw. Usually, the surface or counterplate of the accessory is essentially flat. The clamping plate, in order to permit centering of an attachment screw or bolt passing between forked strut elements of the cycle is frequently formed with essentially parallel grooves or bumps, corresponding to the position or expected position of the struts of the cycle. The clamping plates are stiff and have little elasticity. To properly tighten the clamping screw or bolt without deforming the usually tubular frame struts of the cycle and, on the other hand, prevent loosening under vibration or shock of the bolt, it is necessary to carefully tighten the clamping screw and use appropriate lock washers and the like. In spite of the use of lock washers, however, vibrations and shock which are transmitted to the clamping attachment, and hence to the accessory, are substantial. Overtightening of the clamping bolt, or clamping bolts if a plurality are provided, which might involve complete compression of lock washers, or the like, may result in deformation of the clamping plate and/or of the struts of the cycle to which it is attached. Deforming the struts and/or the clamping plate causes loss of strength of the respectively deformed element and, usually, additionally scars the painted surfaces of the struts of the cycle. The clamping plates usually have sharp edges and, upon cutting through the paint on the frame of the cycle or the struts thereof, the sharp edges damage the paint or enamel covering so that the strut may be subjected to rusting at the point of attachment. The clamping plates may be made of sheet steel or, in some instances, may be made of aluminum, for example as aluminum castings. The clamping plates made of steel are comparatively heavy and require surface treatment to prevent corrosion.
Clamping plates made as aluminum castings, usually pressure castings, are also comparatively heavy since the material utilization factor is poor. In order to permit inexpensive manufacture, the aluminum elements are solid. It is not possible to use recessed screws or Allen-head screws with such elements since the recess of the screw head would decrease the strength of aluminum blocks sufficiently to provide for effective holding. The aluminum pressure plates or pressure blocks cannot be used with all types of cycles, particularly racing and sporting bicycles, since the spacing between the main pedal bearing and the outer circumference of the wheel or tire is insufficient to permit placement of an aluminum cast block or plate.